Additively Manufactured PTC Heater Tubes for Compact Self-Regulating Heating

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Solution Overview

Problem

Existing heater elements for tubes, such as spiral wound resistors and heater tapes, are bulky, require excess space, and need external control to prevent overheating, limiting their efficiency and compactness.

Innovation Solution

The development of a heater tube assembly using additively manufactured positive temperature coefficient (PTC) heater elements and bus bar networks made from conductive ink, which are self-regulating and do not require external control, allowing for a compact and efficient heating solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If spiral wound resistors or heater tapes are used for heating tubes, then heating function is achieved, but the device becomes bulky and requires excess space

Engineering Contradiction:
Improvespace occupied by heater elementVSAvoidoverheating protection capability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The heating element and overheating protection mechanism are merged into a single PTC heater component. The PTC material inherently provides both heating function and self-regulating protection, eliminating the need for separate control systems and reducing overall device volume.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The PTC heater is self-regulating through its inherent positive temperature coefficient property. When the heater reaches a certain temperature, its resistance automatically increases, limiting current flow and preventing overheating without requiring external sensors or control circuits.

Inventive Principle:
Principle #25Self-service

2Reliability

If sensors or thermostats are added to prevent overheating, then safety is improved, but device complexity and space requirements increase

Engineering Contradiction:
Improveoverheating protectionVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The PTC heater material inherently provides overheating protection through its self-regulating electrical properties. The material's resistance automatically increases with temperature, limiting power dissipation and preventing thermal runaway without requiring external sensors, thermostats, or control electronics.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The complex external control system (sensors, thermostats, control circuits) is extracted and replaced by the intrinsic self-regulating property of the PTC material. This simplifies the overall device architecture while maintaining safety and reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Use of energy by moving object

If traditional heater elements are used, then heating is provided, but external control systems are required which reduce efficiency

Engineering Contradiction:
Improveenergy efficiencyVSAvoidcontrol requirement
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The PTC heater automatically regulates its own operation through its temperature-dependent resistance characteristics. It requires no external control systems, sensors, or power management electronics, thereby eliminating energy losses associated with control systems and improving overall energy efficiency.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides a lightweight, compact, and energy-efficient heating system that self-regulates temperature without the need for external controls, ensuring consistent heating and reducing energy consumption.

Implementation Method 1

positive temperature coefficient of resistance (PTC) heating material to limit overheating

Methodology Applied
Scientific EffectPositive temperature coefficient of resistance: Electrical Resistance

Implementation Method 2

resistor heaters that are spiral wound around the core of the tube or tube are used to provide heat

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3637949B1Three dimensionally printed heated positive temperature coefficient tubes
Publication Date: 2022.12.14 GOODRICH CORP
  • EP3637949B1 patent drawingFigure 1A~1B
  • EP3637949B1 patent drawingFigure 2~3
  • EP3637949B1 patent drawingFigure 4~6

AI summary

Additively manufactured heating elements for tubes are made from a positive temperature coefficient heater ink printed on the tube. A bus bar is likewise printed onto the tube using a conductive ink. The positive temperature coefficient heater ink and bust bar conductive ink are encapsulated with a closing adhesive.